System including femoral augment trials and method of performing an orthopaedic joint replacement procedure

ABSTRACT

An orthopedic joint replacement system is shown and described. The system includes a number of prosthetic components configured to be implanted into a patient&#39;s knee. The system also includes a number of surgical instruments configured for use in preparing the bones of the patient&#39;s knee to receive the implants. A method or technique for using the surgical instruments to prepare the bones is also disclosed.

The present application claims priority under 35 U.S.C. § 119 to U.S.patent application Ser. No. 62/338,276, filed May 18, 2016, and havingthe title “SYSTEM AND METHOD FOR PREPARING A PATIENT'S FEMUR IN ANORTHOPAEDIC JOINT REPLACEMENT PROCEDURE,” which is herein incorporatedby reference in its entirety.

CROSS-REFERENCE TO RELATED APPLICATIONS

Cross reference is made to U.S. patent application Ser. No. 62/338,284entitled “SYSTEM AND METHOD FOR PREPARING A PATIENT'S TIBIA IN ANORTHOPAEDIC JOINT REPLACEMENT PROCEDURE;” and U.S. Patent ApplicationSer. No. 62/338,468 entitled “SYSTEM AND METHOD FOR PREPARING APATIENT'S BONE TO RECEIVE A PROSTHETIC COMPONENT,” each of which isassigned to the same assignee as the present application, each of whichis filed concurrently herewith, and each of which is hereby incorporatedby reference.

Cross reference is made to copending U.S. patent application Ser. No.15/598,452 entitled “SYSTEM FOR PREPARING A PATIENT'S FEMUR IN ANORTHOPAEDIC JOINT REPLACEMENT PROCEDURE”; copending U.S. patentapplication Ser. No. 15/598,503 entitled “SYSTEM AND METHOD FORPREPARING A PATIENT'S FEMUR IN AN ORTHOPAEDIC JOINT REPLACEMENTPROCEDURE”; copending U.S. patent application Ser. No. 15/598,521entitled “METHOD FOR PREPARING A PATIENT'S FEMUR IN AN ORTHOPAEDIC JOINTREPLACEMENT PROCEDURE”; and copending U.S. patent application Ser. No.15/598,533 entitled “SYSTEM AND METHOD OF PERFORMING A REAMING OPERATIONON A PATIENT'S FEMUR DURING AN ORTHOPAEDIC JOINT REPLACEMENT PROCEDURE”,each of which is assigned to the same assignee as the presentapplication each of which is filed concurrently herewith, and each ofwhich is hereby incorporated by reference.

TECHNICAL FIELD

The present disclosure relates generally to an orthopaedic prosthesissystem, including prosthetic components and instruments for use in theperformance of an orthopaedic joint replacement procedure, and moreparticularly to orthopaedic prosthetic components and surgicalinstruments for use in the performance of a knee replacement procedure.

BACKGROUND

Joint arthroplasty is a well-known surgical procedure by which adiseased and/or damaged natural joint is replaced by a prosthetic joint.For example, in a total knee arthroplasty surgical procedure, apatient's natural knee joint is partially or totally replaced by aprosthetic knee joint or knee prosthesis. A typical knee prosthesisincludes a tibial tray, a femoral component, and a polymer insert orbearing positioned between the tibial tray and the femoral component.The tibial tray generally includes a plate having a stem extendingdistally therefrom, and the femoral component generally includes a pairof spaced apart condylar elements, which include surfaces thatarticulate with corresponding surfaces of the polymer bearing. The stemof the tibial tray is configured to be implanted in asurgically-prepared medullary canal of the patient's tibia, and thefemoral component is configured to be coupled to a surgically-prepareddistal end of a patient's femur

From time-to-time, a revision knee surgery may need to be performed on apatient. In such a revision knee surgery, the previously-implanted kneeprosthesis, sometimes referred to a “primary knee prosthesis,” issurgically removed and a replacement or revision knee prosthesis isimplanted. In some revision knee surgeries, all of the components of theprimary knee prosthesis, including, for example, the tibial tray, thefemoral component, and the polymer bearing, may be surgically removedand replaced with revision prosthetic components. In other revision kneesurgeries, only part of the previously-implanted knee prosthesis may beremoved and replaced.

During a revision knee surgery, the orthopaedic surgeon typically uses avariety of different orthopaedic surgical instruments such as, forexample, cutting blocks, surgical reamers, drill guides, prosthetictrials, and other surgical instruments to prepare the patient's bones toreceive the knee prosthesis. Other orthopaedic surgical instruments suchas trial components may be used to size and select the components of theknee prosthesis that will replace the patient's natural joint. Trialcomponents may include a femoral trial that may be used to size andselect a prosthetic femoral component, a tibial tray trial that may beused to size and select a prosthetic tibial tray, and a stem trial thatmay be used to size and select a prosthetic stem component.

SUMMARY

An orthopaedic joint replacement system is shown and described. Thesystem includes a number of prosthetic components configured to beimplanted into a patient's knee. The system also includes a number ofsurgical instruments configured for use in preparing the bones of thepatient's knee to receive the implants. A method or technique for usingthe surgical instruments to prepare the bones is also disclosed.

According to one aspect of the disclosure, an orthopaedic surgicalsystem includes a first surgical reamer including a distal end includinga plurality of cutting flutes, a first elongated shaft extending awayfrom the distal end, and a shank configured to be coupled to a surgicaldrill. The first elongated shaft has a first diameter. A second surgicalreamer includes a distal end including a plurality of cutting flutes, asecond elongated shaft extending away from the distal end, and a shankconfigured to be coupled to a surgical drill. The second elongated shafthas a second diameter greater than the first diameter. A depth stopincludes a central opening having a third diameter that is equal to thesecond diameter. The depth stop is configured to be separately coupledto one of the first elongated shaft and the second elongated shaft. Thedepth stop includes a plurality of alignment tabs extending into thecentral opening. Each pair of opposing alignment tabs defines a widththat is less than the first diameter of the first surgical reamer. Aplurality of longitudinal slots are defined in each of the firstelongated shaft and the second elongated shaft and each longitudinalslot is sized to receive one of the alignment tabs of the depth stop.

In some embodiments, the first elongated shaft of the first surgicalreamer may have a plurality of apertures each positioned at a differentdistance from the distal end along a longitudinal axis of the firstelongated shaft. The depth stop may have a moveable plate operable toseparately engage each aperture to secure the depth stop in positionalong the first elongated shaft. In some embodiments, the secondelongated shaft of the second surgical reamer may have a plurality ofapertures each positioned at a different distance from the distal endalong a longitudinal axis of the second elongated shaft. The moveableplate of the depth stop may be operable to separately engage eachaperture to secure the depth stop in position along the second elongatedshaft. In some embodiments, the moveable plate may have a pin sized tobe received in each aperture. The pin may be configured to extendorthogonal to the longitudinal axes of the first and second elongatedshafts. In some embodiments, the pin may extend parallel to a pair ofalignment tabs of the depth stop. In some embodiments, each of the firstelongated shaft and the second elongated shaft may have a plurality ofannular slots. Each annular slot may be associated with one of theapertures and may correspond to a predetermined distance from the distalend.

In some embodiments, the alignment tabs of the depth stop may have afirst pair of opposing alignment tabs. A second pair of opposingalignment tabs may extend orthogonal to the first pair of alignment tabsand may cooperate with the first pair of opposing alignment tabs todefine an alignment opening in the depth stop. In some embodiments, thedepth stop may have a first planar surface and a second planar surfacepositioned opposite the first planar surface. The central opening mayextend through the first planar surface and the second planar surface.The first pair of opposing alignment tabs and the second pair ofopposing alignment tabs may extend inwardly from the first planarsurface. In some embodiments, the alignment tabs of the depth stop mayhave a third pair of opposing alignment tabs extending inwardly from thesecond planar surface. A fourth pair of opposing alignment tabs mayextend orthogonal to the third pair of alignment tabs. The fourth pairof opposing alignment tabs may extend inwardly from the second planarsurface.

In some embodiments, each longitudinal slot of the first elongated shaftmay extend inwardly from an elongated opening defined in the firstelongated shaft to a base surface. A first distance may be definedbetween each opposing base surface of the first elongated shaft. Eachlongitudinal slot of the second elongated shaft may extend inwardly froman elongated opening defined in the second elongated shaft to a basesurface. A second distance may be defined between each opposing basesurface of the second elongated shaft. The second distance may be equalto first distance and less than the width of the depth stop. In someembodiments, a guide body may have a passageway sized to receive thefirst elongated shaft. The depth stop may be configured to engage anouter end of the guide body.

According to another aspect of the disclosure, an orthopaedic surgicalsystem includes a surgical reamer including a distal end including aplurality of cutting flutes, an elongated shaft extending away from thedistal end, and a shank configured to be coupled to a surgical drill.The elongated shaft includes a plurality of longitudinal slots and aplurality of apertures defined in a base surface of one of the pluralityof longitudinal slots. A depth stop includes a central opening sized toreceive the elongated shaft, a moveable plate operable to separatelyengage each aperture to secure the depth stop in position along theelongated shaft, and a plurality of alignment tabs extending into thecentral opening and positioned to be received in the plurality ofelongated slots of the surgical reamer.

In some embodiments, the moveable plate may have a pin sized to bereceived in each aperture. The pin may be configured to extendorthogonal to a longitudinal axis of the elongated shaft. In someembodiments, the pin may extend parallel to a pair of alignment tabs ofthe depth stop. In some embodiments, the elongated shaft may have aplurality of annular slots. Each annular slot may be associated with oneof the apertures and may correspond to a predetermined distance from thedistal end of the surgical reamer. In some embodiments, the alignmenttabs of the depth stop may have a first pair of opposing alignment tabs.A second pair of opposing alignment tabs may extend orthogonal to thefirst pair of alignment tabs and may cooperate with the first pair ofopposing alignment tabs to define an alignment opening in the depthstop. In some embodiments, the depth stop may have a biasing elementoperable to bias the pin into engagement with the aperture.

According to yet another aspect of the disclosure, a method ofperforming an orthopaedic surgery includes aligning a central opening ofa depth stop with an elongated shaft of a first surgical reamer. Themethod also includes advancing the depth stop over the elongated shaftto position a plurality of alignment tabs of the depth stop into aplurality of longitudinal slots defined in the elongated shaft. Themethod also includes securing the depth stop in position along theelongated shaft. The method also includes advancing the first surgicalreamer into a guide body to engage the depth stop with the guide bodyand define an opening in a patient's bone.

In some embodiments, securing the depth stop may require positioning apin in an aperture defined in the elongated shaft. In some embodiments,the method may require pressing a button to disengage the pin from theaperture.

According to an aspect of the disclosure, an orthopaedic surgical systemincludes a femoral trial component configured to be coupled to asurgically-prepared distal end of a patient's femur. The femoral trialcomponent includes an anterior flange and a pair of curved armsextending away from the anterior flange. Each arm includes a distalbone-facing surface. A plurality of augment trial components isprovided. Each augment trial component is sized to be positioned on thedistal bone-facing surface and includes a mounting post and a magnet.Each curved arm includes a slot defined in its distal bone-facingsurface that extends inwardly from an outer edge. The slot is sized toreceive the mounting post of one of the plurality of augment trialcomponents.

In some embodiments, each augment trial component may have a differentthickness. The curved arms of the femoral trial component may have aplurality of distal cutting slots. Each distal cutting slot may bespaced apart from the distal bone-facing surface by a distance equal tothe thickness of one of the augment trial components. In someembodiments, each curved arm may have a channel that may be defined inits distal bone-facing surface and extend inwardly from the outer edgeparallel to the slot. Each augment trial component may have a peg sizedto be received in the channel. In some embodiments, the channel may bepartially defined by a tapered surface configured to engage the peg ofeach augment trial component. In some embodiments, each curved arm mayhave an aperture that may be defined in its distal bone-facing surfaceand spaced apart from the channel. Each aperture may be sized to receivethe peg of each augment trial component. In some embodiments, eachaugment trial component may have a planar base surface configured toengage the distal bone-facing surface of each curved arm. The mountingpost and the peg may extend outwardly from the base surface.

In some embodiments, a plurality of posterior augment trial componentsmay be provided. Each augment trial component may have a mounting postand a magnet. Each arm may have a posterior bone-facing surface and aposterior slot defined in its posterior bone-facing surface that extendsinwardly from the outer edge. The posterior slot may be sized to receivethe mounting post of one of the plurality of posterior augment trialcomponents. In some embodiments, each posterior augment trial componentmay have a different thickness. The curved arms of the femoral trialcomponent may have a plurality of posterior cutting slots. Eachposterior cutting slot may be spaced apart from the posteriorbone-facing surface by a distance equal to the thickness of one of theposterior augment trial components.

In some embodiments, a femoral trial insert component may be configuredto be secured to the femoral trial component. The femoral trial insertcomponent may have a main body sized to be positioned between the pairof curved arms. In some embodiments, a tibial base plate may be sized tobe positioned on a proximal surface of a patient's tibia. An inserttrial may be configured to be attached to the tibial base plate. Theinsert trial may have a pair of proximal curved surfaces configured toarticulate with the curved arms of the femoral trial component and thefemoral trial insert component.

In some embodiments, the mounting post may have a pin operable to retainthe mounting post in the slot of the curved arm.

According to another aspect of the disclosure, an orthopaedic surgicalsystem includes a femoral trial component configured to be coupled to asurgically-prepared distal end of a patient's femur. The femoral trialcomponent includes an anterior flange, and a pair of curved armsextending away from the anterior flange. A plurality of augment trialcomponents is provided. Each augment trial component includes a peg anda magnet. Each curved arm includes an aperture defined in a bone-facingsurface that is sized to receive the peg of one of the plurality ofaugment trial components.

In some embodiments, the bone-facing surface may be a distal bone-facingsurface. In some embodiments, the bone-facing surface may be a posteriorbone-facing surface.

In some embodiments, each curved arm may have a channel that may definedin its bone-facing surface. The channel may extend inwardly from anouter edge of the curved arm and spaced apart from the aperture. Thechannel may be sized to receive the peg of each augment trial component.In some embodiments, each augment trial component may have a mountingpost. Each curved arm may have a slot defined in the bone-facing surfacethat extends inwardly from the outer edge. The slot may be sized toreceive the mounting post of one of the plurality of augment trialcomponents.

In some embodiments, each augment trial component may have a differentthickness. The curved arms of the femoral trial component may have aplurality of cutting slots. Each cutting slot may be spaced apart fromthe bone-facing surface by a distance equal to the thickness of one ofthe augment trial components.

According to yet another aspect of the disclosure, an orthopaedicsurgical system includes a femoral trial component configured to becoupled to a surgically-prepared distal end of a patient's femur. Thefemoral trial component includes an anterior flange, and a pair ofcurved arms extending away from the anterior flange. A plurality ofaugment trial components is provided. Each augment trial componentincludes a mounting post and a magnet. Each curved arm includes a slotdefined in a bone-facing surface that extends inwardly from an outeredge. The slot is sized to receive the mounting post of one of theplurality of augment trial components.

In some embodiments, the bone-facing surface may have a distalbone-facing surface. In some embodiments, the bone-facing surface mayhave a posterior bone-facing surface.

According to an aspect of the disclosure, an orthopaedic surgical systemincludes a femoral trial component configured to be coupled to asurgically-prepared distal end of a patient's femur. The femoral trialcomponent includes an anterior flange. A pair of curved arms extendsaway from the anterior flange. A posterior flange extends between thepair of curved arms. A cutting block is configured to be coupled to theanterior flange of the femoral trial component. The cutting blockincludes a cutting guide surface. When the cutting block is coupled tothe anterior flange of the femoral trial component, the cutting guidesurface is positioned coplanar with a distal surface of the anteriorflange of the femoral trial component and the posterior flange of thefemoral trial component is aligned with the cutting guide surface of thecutting block to prevent further posterior movement of a cutting sawblade.

In some embodiments, the anterior flange of the femoral trial componentmay have an aperture. The cutting block may have a body having thecutting guide surface and a post extending from the body that may besized to be received in the aperture.

In some embodiments, the cutting block may have a locking mechanismoperable to secure the cutting block to the femoral trial component. Insome embodiments, the anterior flange of the femoral trial component mayhave a slot. The locking mechanism may have a moveable locking tabextending outwardly from the body and sized to be received in the slot.The locking tab may be moveable between a first position in which thelocking tab may be configured to engage the anterior flange to securethe cutting block to the femoral trial component and a second positionin which the locking tab may be configured to be spaced apart from theanterior flange. In some embodiments, the locking mechanism may have auser-operated button positioned opposite the cutting guide surface. Theuser-operated button may be operable to actuate the locking tab. In someembodiments, the locking mechanism may have a biasing element to biasthe locking tab in the first position.

In some embodiments, the posterior plate may have a groove coplanar withthe distal surface of the anterior flange. In some embodiments, theposterior plate may have a visual indicator that may be coplanar withthe distal surface of the anterior flange.

In some embodiments, the curved arms of the femoral trial component mayhave a plurality of distal cutting slots extending parallel to thedistal surface of the anterior flange. In some embodiments, the curvedarms of the femoral trial component may have a plurality of posteriorcutting slots extending orthogonal to the distal cutting slots.

In some embodiments, a tibial base plate may be sized to be positionedon a proximal surface of a patient's tibia. An insert trial may beconfigured to be attached to the tibial base plate. The insert trial mayhave a pair of proximal curved surfaces configured to articulate withthe curved arms of the femoral trial component.

According to another aspect of the disclosure, an orthopaedic surgicalsystem includes a femoral trial component configured to be coupled to asurgically-prepared distal end of a patient's femur. The femoral trialcomponent includes an anterior flange. A pair of curved arms extendsaway from the anterior flange. A posterior flange extends between thepair of curved arms. A central passageway is defined between theanterior flange, the curved arms, and the posterior flange. A femoraltrial insert component is configured to be secured to the femoral trialcomponent. The femoral trial insert component includes a main body sizedto be positioned in the central passageway of the femoral trialcomponent. A cutting block is configured to be coupled to the anteriorflange of the femoral trial component. The cutting block includes acutting guide surface. When the cutting block is coupled to the anteriorflange of the femoral trial component, the cutting guide surface ispositioned coplanar with a distal surface of the anterior flange of thefemoral trial component.

In some embodiments, the main body of the femoral trial insert componentmay have a curved surface that may be shaped to match a patella surfaceof a prosthetic femoral component. In some embodiments, the posteriorflange of the femoral trial component may be aligned with the cuttingguide surface of the cutting block to prevent further posterior movementof a cutting saw blade.

According to another aspect of the disclosure, a method includescoupling a femoral trial component to a surgically-prepared distal endof a patient's femur. The method also includes coupling a cutting blockto an anterior flange of the femoral trial component such that a cuttingguide of the cutting block is positioned coplanar with a distal surfaceof the anterior flange. The method also includes advancing a saw bladealong the cutting guide of the cutting block and the distal surface ofthe anterior flange into contact with a patient's femur to cut thepatient's femur. The method also includes advancing the saw bladeposteriorly to engage the saw blade with a posterior flange of thefemoral trial component.

In some embodiments, the method may require cutting the distal end ofthe patient's femur along an inner surface of each of the medial arm andthe lateral arm.

In some embodiments, the method may require positioning a locking tabextending from the cutting block within a corresponding aperture formedin the anterior flange of the femoral trial component to secure thecutting block to the femoral trial component. In some embodiments, themethod may require actuating a user-operated button formed on thecutting block to actuate the locking tab. In some embodiments, themethod may require coupling a femoral trial insert component to thefemoral trial component such that a body of the insert may be positionedin a central passageway defined between a medial arm and a lateral armof the femoral trial component and between the anterior flange andposterior flange of the femoral trial component. In some embodiments,the method may require articulating the patient's leg between extensionand flexion with the femoral trial component engaged with an inserttrial component located on a patient's tibia.

According to one aspect of the disclosure, an orthopaedic surgicalsystem includes a tibial base plate sized to be positioned on a proximalsurface of a patient's tibia. An insert trial component is configured tobe attached to the tibial base plate. The insert trial componentincludes a pair of proximal curved concave surfaces. A femoral trialcomponent is configured to be coupled to a distal end of a patient'sfemur. The femoral trial component includes an anterior flange. A pairof curved arms extends away from the anterior flange. Each arm includesa curved condyle surface and a plurality of cutting guide slots. Afemoral trial insert component includes a central body sized to bepositioned between the pair of curved arms and a pair of mountingflanges extending outwardly from the central body. Each mounting flangeincludes a distal surface and a fastener retained in each mountingflange to secure the mounting flange to the femoral trial component. Thefemoral trial component includes a pair of slots in the curved armssized to receive the mounting flanges of the femoral trial insertcomponent. The distal surfaces and the curved condyle surfaces areconfigured to engage and articulate on the proximal curved concavesurfaces of the insert trial component when the femoral trial insertcomponent is secured to the femoral trial component.

In some embodiments, the femoral trial insert component may have a tabextending outwardly from a first flange of the pair of mounting flanges.The femoral trial component may have a groove defined in a firstmounting curved arm of the pair of curved arms. The groove may beconnected to a first slot of the pair of slots and may be sized toreceive the tab of the femoral trial insert component to orient thefemoral trial insert component relative to the femoral trial component.In some embodiments, the pair of curved arms may have a second curvedarm devoid of any grooves opening into the other slot of the pair ofslots. In some embodiments, the femoral trial insert component may havea second tab extending outwardly from the first mounting flange. Thefemoral trial component may have a second groove defined in the firstcurved arm. The second groove may be connected to the first slot and maybe sized to receive the second tab of the femoral trial insert componentto orient the femoral trial insert component relative to the femoraltrial component.

In some embodiments, each fastener may have an elongated threaded shaftsized to engage a threaded bore defined in one of the mounting flangesof the femoral trial component. A head may be connected to the elongatedthreaded shaft. A socket may be defined in the head. An annular flangemay extend radially outward from the head to engage the mounting flangeof the femoral trial component. In some embodiments, each mountingflange may have an opening defined in the distal surface of the mountingflange. An inner wall may extend inwardly from the opening to define acavity in the mounting flange. The inner wall may have a distal sectiondefining a first diameter. The annular flange of the fastener may have asecond diameter greater than the first diameter. In some embodiments,the annular flange of the fastener may have a beveled proximal edge.

In some embodiments, the central body of the femoral trial insertcomponent may have an anterior flange. A pair of arms may extend fromthe anterior flange. Each arm may have one of the mounting flanges. Aproximal wall may extend between the pair of arms. The proximal wall maycooperate with the pair of arms and the anterior flange to define anotch sized to receive a spine of the insert trial component. Aposterior cam may extend from the proximal wall and may be configured toarticulate with the spine of the insert trial component over a range offlexion.

In some embodiments, the femoral trial insert component may be a firstfemoral trial component. The orthopaedic surgical system may have asecond femoral trial component that may have an anterior flange. A pairof arms may extend from the anterior flange. Each arm of the secondfemoral trial component may have a mounting flange having a distalsurface and a fastener retained in the mounting flange to secure themounting flange to the femoral trial component. An open channel may bedefined between the pair of arms.

In some embodiments, the femoral trial insert component may have a postsized to receive a stem trial including an elongated shaft. In someembodiments, the femoral trial insert component may have an anteriorsurface shaped to match a patella surface of a corresponding femoralprosthetic component.

According to another aspect of the disclosure, an orthopaedic surgicalsystem includes a stem trial including a threaded distal end and anelongated shaft extending from the threaded distal end. A femoral trialcomponent is configured to be coupled to a distal end of a patient'sfemur. The femoral trial component includes an anterior flange. A pairof curved arms extends away from the anterior flange. Each arm includesa curved condyle surface and a plurality of cutting guide slots. Afemoral box trial component includes a central body sized to bepositioned between the pair of curved arms. A post is sized toseparately receive the threaded distal end of the stem trial. A pair ofmounting flanges extends outwardly from the central body. Each mountingflange includes a distal surface and a fastener retained in eachmounting flange to secure the femoral box trial component to the femoraltrial component. A femoral intramedullary component includes a postsized to separately receive the threaded distal end of the stem trial.Each of a pair of mounting flanges includes a distal surface and afastener retained in each mounting flange to secure the femoral boxtrial component to the femoral trial component. The femoral trialcomponent includes a pair of slots in the curved arms sized toseparately receive the mounting flanges of the femoral box trialcomponent and the femoral intramedullary component.

In some embodiments, an insert trial component may have a pair ofproximal curved concave surfaces configured to articulate with thecurved condyle surfaces of the femoral trial component. In someembodiments, the central body may have a posterior cam configured toengage a spine of the insert trial component. In some embodiments, thedistal surfaces of the femoral box trial component and the femoralintramedullary component articulate on the proximal curved concavesurfaces of the insert trial component when secured to the femoral trialcomponent.

According to another aspect of the disclosure, an orthopaedic surgicalsystem includes a femoral trial component configured to be coupled to adistal end of a patient's femur. The femoral trial component includes ananterior flange. A pair of curved arms extends away from the anteriorflange. Each arm includes a curved condyle surface and a plurality ofcutting guide slots. A femoral trial insert component includes (i) apair of mounting flanges extending outwardly from the central body, eachmounting flange including a distal surface and a fastener retainedtherein to secure the mounting flange to the femoral trial component,and a tab extending outwardly from a first flange of the pair ofmounting flanges. The femoral trial component includes a pair of slotsin the curved arms sized to receive the mounting flanges of the femoraltrial insert component and a groove defined in a first mounting curvedarm of the pair of curved arms, the groove being connected to a firstslot of the pair of slots and sized to receive the tab of the femoraltrial insert component to orient the femoral trial insert componentrelative to the femoral trial component.

In some embodiments, the pair of curved arms may have a second curvedarm devoid of any grooves opening into the other slot of the pair ofslots. In some embodiments, the femoral trial insert component may havea second tab extending outwardly from the first mounting flange. Thefemoral trial component may have a second groove defined in the firstcurved arm. The second groove may be connected to the first slot andsized to receive the second tab of the femoral trial insert component toorient the femoral trial insert component relative to the femoral trialcomponent.

In some embodiments, each fastener may have an elongated threaded shaftsized to engage a threaded bore defined in one of the mounting flangesof the femoral trial component. A head may be connected to the elongatedthreaded shaft. A socket may be defined in the head. An annular flangemay extend radially outward from the head to engage the mounting flangeof the femoral trial component. In some embodiments, each mountingflange may have an opening defined in the distal surface of the mountingflange. An inner wall may extend inwardly from the opening to define acavity in the mounting flange. The inner wall may have a distal sectiondefining a first diameter. The annular flange of the fastener may have asecond diameter greater than the first diameter.

According to another aspect, a method of performing an orthopaedicsurgical procedure comprises positioning a femoral trial component on adistal end of a patient's femur, advancing a cutting saw blade through acutting guide slot defined in the femoral trial component to remove aportion of the patient's femur, attaching a femoral trial insertcomponent to the femoral trial component via a pair of fastenersretained on the femoral trial insert component, and engaging surfaces ofthe femoral trial component and the femoral trial insert component witha pair of concave curved surfaces of a tibial insert trial componentover a range of flexion from extension to flexion.

In some embodiments, attaching the femoral trial insert component mayinclude securing the femoral trial insert component to the femoral trialcomponent while the femoral trial component is positioned on the distalend of a patient's femur.

In some embodiments, the method may further comprise attaching anaugment trial to a bone-facing surface of the femoral trial component.Additionally, in some embodiments, attaching the augment trial to thebone-facing surface of the femoral trial component may include advancinga mounting post of the augment trial into a slot extending inwardly froman outer edge of the femoral trial component. In some embodiments,attaching the augment trial to the bone-facing surface of the femoraltrial component may include engaging a peg of the augment trial with atapered surface of a channel defined in the bone-facing surface of thefemoral trial component to cause the augment trial to tilt relative tothe bone-facing surface.

In some embodiments, attaching the femoral trial insert component mayinclude advancing a pair of flanges into openings defined in a pair ofcurved arms of the femoral trial component. The fasteners may beretained on the pair of flanges. Additionally, in some embodiments,advancing the pair of flanges into openings defined in the pair ofcurved arms of the femoral trial component includes advancing analignment tab extending from a first flange of the pair of flanges intoan alignment groove defined in a first curved arm of the pair of curvedarms. The second curved arm of the pair of curved arms may be devoid ofany alignment grooves.

In some embodiments, the method may further comprise attaching a posttrial insert component to the femoral trial component via a pair offasteners retained on the femoral trial insert component, engagingsurfaces of the post trial component and the femoral trial insertcomponent with a pair of concave curved surfaces of a tibial inserttrial component over a range of flexion from extension to flexion, andremoving the post trial insert component from the femoral trialcomponent. The femoral trial insert component may be a femoral box trialcomponent, and attaching the femoral trial insert component to thefemoral trial component may include attaching femoral box trialcomponent after removing the post trial insert component from thefemoral trial component.

In some embodiments, the method may further comprise coupling a cuttingblock to an anterior flange of the femoral trial component such that acutting guide of the cutting block is positioned coplanar with a distalsurface of the anterior flange, advancing a saw blade along the cuttingguide of the cutting block and the distal surface of the anterior flangeinto contact with a patient's femur to cut the patient's femur, andadvancing the saw blade posteriorly to engage the saw blade with aposterior flange of the femoral trial component. Additionally, in someembodiments, attaching the femoral trial insert component includesattaching the femoral trial insert component to the femoral trialcomponent after advancing the saw blade posteriorly to engage the sawblade with a posterior flange of the femoral trial component.

In some embodiments, the method may further comprise attaching a drillguide body to the femoral trial component via a pair of retained screws,and advancing a surgical reamer through the drill guide body to definean opening in the patient's femur. Additionally, in some embodiments,the method may further comprise securing a depth stop in position alongan elongated shaft of the surgical reamer, and advancing the surgicalreamer into the drill guide body to engage the depth stop with the guidebody.

In some embodiments, may further comprise securing a stem trial to thefemoral trial insert component.

According to another aspect, the method of performing an orthopaedicsurgical procedure comprises attaching a first femoral trial insertcomponent to a femoral trial component, positioning the first femoraltrial insert component and the femoral trial component on a distal endof a patient's femur, and engaging surfaces of the femoral trialcomponent and the first femoral trial insert component with a pair ofconcave curved surfaces of a tibial insert trial component over a rangeof flexion from extension to flexion. The method also comprisesadvancing a cutting saw blade through a cutting guide slot defined inthe femoral trial component to remove a portion of the patient's femur,advancing an augment trial medially into a slot defined in the femoraltrial component to position a body of the augment trial between abone-facing surface of the femoral trial component and the patient'sfemur, and detaching the first femoral trial insert component from thefemoral trial component. The method also includes coupling a cuttingblock to an anterior flange of the femoral trial component, advancing asaw blade along the cutting guide of the cutting block and the distalsurface of the anterior flange into contact with a patient's femur tocut the patient's femur, attaching a second femoral trial insertcomponent to the femoral trial component, and engaging surfaces of thefemoral trial component and the second femoral trial insert componentwith a pair of concave curved surfaces of a tibial insert trialcomponent over a range of flexion from extension to flexion.

In some embodiments, the method may further comprise advancing the sawblade posteriorly to engage the saw blade with a posterior flange of thefemoral trial component.

In some embodiments, advancing the cutting saw blade through the cuttingguide slot may include selecting a cutting guide slot positioned adistance from the bone-facing surface of the femoral trial componentthat is equal to a thickness of the augment trial component.

In some embodiments, the method may further comprise attaching a drillguide body to the femoral trial component via a pair of retained screws,and advancing a surgical reamer through the drill guide body to definean opening in the patient's femur.

In some embodiments, the method may further comprise securing a stemtrial to the first femoral trial insert component prior to attaching thefirst femoral trial insert component to the femoral trial component.

According to another aspect, the method of performing an orthopaedicsurgical procedure comprises positioning a femoral trial component on adistal end of a patient's femur, selecting a cutting guide slotpositioned a distance from the bone-facing surface of the femoral trialcomponent that is equal to a thickness of an augment trial component,advancing a cutting saw blade through a cutting guide slot defined inthe femoral trial component to remove a portion of the patient's femur,and advancing a mounting post of the augment trial into a slot extendinginwardly from an outer edge of the femoral trial component.

In some embodiments, advancing the mounting post of the augment trialinto the slot may include positioning a body of the augment trialbetween a bone-facing surface of the femoral trial component and thepatient's femur.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description particularly refers to the following figures,in which:

FIG. 1 is an exploded perspective view of prosthetic components of anorthopaedic joint replacement system;

FIG. 2 is an exploded perspective view of surgical instruments of theorthopedic joint replacement system for use in preparing a patient'sfemur;

FIG. 2A is a cross-sectional side elevation view taken along the line2-2 in FIG. 2;

FIG. 3 is a distal plan view of a femoral cutting guide of the surgicalinstruments of FIG. 2;

FIG. 4 is an anterior elevation view of the femoral cutting guide ofFIGS. 2-3;

FIG. 5 is a side elevation view of the femoral cutting guide of FIGS.2-4;

FIGS. 6-7 illustrate steps of an orthopaedic surgical procedure usingthe orthopaedic joint replacement system;

FIG. 8 is a perspective view of a pair of surgical instruments of theorthopedic joint replacement system;

FIG. 8A is a cross-sectional plan view of the instruments of FIG. 8taken along the line 8-8 in FIG. 8;

FIGS. 9-11, 12, 12A, 13A, 13B, 14, 15A, 15B, and 16-19 illustrate othersteps of the orthopaedic surgical procedure using the orthopaedic jointreplacement system.

FIG. 20 is a proximal perspective view of the femoral cutting guide ofFIGS. 9-5;

FIG. 21 is a perspective view of the femoral augment trial shown in FIG.14;

FIG. 22 is a side elevation view of the femoral augment trial of FIG.21; and

FIG. 23 is a further illustration of a step of the orthopaedic surgicalprocedure using the orthopaedic joint replacement system.

DETAILED DESCRIPTION OF THE DRAWINGS

While the concepts of the present disclosure are susceptible to variousmodifications and alternative forms, specific exemplary embodimentsthereof have been shown by way of example in the drawings and willherein be described in detail. It should be understood, however, thatthere is no intent to limit the concepts of the present disclosure tothe particular forms disclosed, but on the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention as defined by the appended claims.

Terms representing anatomical references, such as anterior, posterior,medial, lateral, superior, inferior, etcetera, may be used throughoutthe specification in reference to the orthopaedic implants andorthopaedic surgical instruments described herein as well as inreference to the patient's natural anatomy. Such terms havewell-understood meanings in both the study of anatomy and the field oforthopaedics. Use of such anatomical reference terms in the writtendescription and claims is intended to be consistent with theirwell-understood meanings unless noted otherwise.

The exemplary embodiments of the present disclosure are described andillustrated below to encompass prosthetic knee joints and knee jointcomponents, as well as methods of implanting and reconstructing kneejoints. It will also be apparent to those of ordinary skill in the artthat the preferred embodiments discussed below are exemplary in natureand may be reconfigured without departing from the scope and spirit ofthe present invention. However, for clarity and precision, the exemplaryembodiments as discussed below may include optional steps, methods, andfeatures that one of ordinary skill should recognize as not being arequisite to fall within the scope of the present invention.

Referring now to FIG. 1, the orthopaedic joint replacement system 10includes a number of orthopaedic prosthetic components 12 and a numberof orthopaedic surgical instruments 14 (see, for example, FIG. 2) foruse in preparing the bone to receive one or more of the prostheticcomponents 12. What is meant herein by the term “orthopaedic surgicalinstrument” or “orthopaedic surgical instrument system” is a surgicaltool for use by a surgeon in performing an orthopaedic surgicalprocedure. As such, it should be appreciated that, as used herein, theterms “orthopaedic surgical instrument” and “orthopaedic surgicalinstruments” are distinct from orthopaedic prosthetic components orimplants, such as those shown in FIG. 1.

The prosthetic components 12 of the system 10 include a prostheticfemoral component 20 configured to be secured to a surgically-prepareddistal end of a patient's femur and a prosthetic tibial component 22configured to be secured to a surgically-prepared proximal end of thepatient's tibia. In the illustrative embodiment, the tibial component 22includes a tibial tray 24 and a prosthetic insert 26 configured toengage the femoral component 20 after implantation into a patient'sknee. It should be appreciated that the system 10 may include a numberof components 12 corresponding to patients having bones of varyingsizes. In that way, a surgeon will be able to select the components andother instruments that most-closely match the patient's bony anatomy.

As shown in FIG. 1, the femoral component 20 includes an anterior flange30 and a pair of condyles 32 extending away from the flange 30. A notch34, commonly called an intra-condylar notch, is defined between thecondyles 32. The condyles 32 define articulation surfaces 36 configuredto engage corresponding articulation surfaces 70 of the insert 26. Thefemoral component 20 also includes an elongated stem post 40, whichextends superiorly away from its backside surface 42. As described ingreater detail below, the femoral stem post 40 is configured to receiveone of a number of different stem components 44. In the illustrativeembodiment, a threaded bore 48, which is sized to receive acorresponding threaded shaft 50 of a stem component 44, is defined inthe stem post 40.

The tibial tray 24 is configured to be implanted into asurgically-prepared end of a patient's proximal tibia (not shown). Thetibial tray 24 includes a platform 58 having an elongated stem post 60extending inferiorly away from its inferior surface 62. The elongatedtibial stem post 60 is configured to receive one of a number ofdifferent stem components 44. Specifically, as can be seen in FIG. 1, athreaded bore 48, which is sized to receive a corresponding threadedshaft 50 of a stem component 44, is defined in the stem post 60.

The insert 26 is securable to the tibial tray 24. In particular, theinsert 26 may be snap-fit to the tibial tray 24. In such a way, theinsert 26 is fixed relative to the tibial tray 24 (i.e., it is notrotatable or moveable in the anterior/posterior or medial/lateraldirections). Although, in other embodiments, the tibial tray may besecured in a manner that allows it to rotate relative to the tibial tray24.

The insert 26 includes lateral and medial articulation surfaces 70. Thesurfaces 70 are configured to articulate with the correspondingarticulation surfaces 36 of the femoral component 20. Specifically, thefemoral component 20 is configured to be implanted into asurgically-prepared distal end of the patient's femur (not shown), andis configured to emulate the configuration of the patient's naturalfemoral condyles. As such, the articulation surfaces 36 of the femoralcomponent 20 are configured (e.g., curved) in a manner which mimics thecondyles of the natural femur.

As shown in FIG. 1, the stem components 44 of the system 10 includeelongated stems 80, which are configured to be attached to either of thecomponents 20, 22. Each elongated stem 80 extends from the threadedshaft 50 at one end to a pointed tip 82 at the opposite end. Each stemalso includes a ribbed outer surface 84 extending from the pointed tip82 toward the threaded shaft 50. A plurality of substantially planarsurfaces 86 are positioned around the outer circumference of the stem 80adjacent to the shaft 50. The surfaces 86 are sized and positioned toreceive the end of a wrench or other installation tool so that the stem80 may be rotated into tight engagement with one of the threaded bores48.

In the illustrative embodiment, the prosthetic components 12 alsoinclude a plurality of offset adapters 90, 92 configured to be attachedto the components 20, 22. As shown in FIG. 1, the adapter 90 isconfigured to offset the longitudinal axis of the elongated stem 80 fromthe longitudinal axis of the stem post 60 of the tibial tray 24 by apredetermined amount. Similarly, the adapter 92 is configured to offsetthe longitudinal axis of the elongated stem 80 from the longitudinalaxis of the stem post 40 of the femoral component 20. Each of theadapters 90, 92 includes a threaded shaft 50 configured to be receivedin the threaded bore 48 of either of the components 20, 22. Each of theadapters 90, 92 also includes a threaded bore 48 at its opposite end,which is sized to receive a threaded shaft 50 of one of the elongatedstems 80. In the illustrative embodiment, a locking nut 100 ispositioned on the threaded shaft 50 of each of the adapters 90, 92. Thelocking nut 100 may be tightened against the surface of the stem post ofeach component to secure the adapter thereto.

The components of the knee prosthesis 10 that engage the natural bone,such as the femoral component 20, the tibial tray 24, and the stemcomponents 44, may be constructed with an implant-grade biocompatiblemetal, although other materials may also be used. Examples of suchmetals include cobalt, including cobalt alloys such as a cobalt chromealloy, titanium, including titanium alloys such as a Ti6Al4V alloy, andstainless steel. Such a metallic components may also be coated with asurface treatment, such as hydroxyapatite, to enhance biocompatibility.Moreover, the surfaces of the metallic components that engage thenatural bone may be textured to facilitate securing the components tothe bone. Such surfaces may also be porous coated to promote boneingrowth for permanent fixation.

The insert 26 may be constructed with a material that allows for smootharticulation between the insert 26 and the femoral component 20, such asa polymeric material. One such polymeric material is polyethylene suchas ultrahigh molecular weight polyethylene (UHMWPE).

Referring now to FIG. 2, a number of orthopedic surgical instruments 14for use in preparing the femoral bone to receive one or more of theprosthetic components 12 are shown. The instruments 14 include a femoraltrial component 410 and a femoral trial insert component 412 configuredto be secured to the femoral trial component. The instruments 14 alsoinclude a cutting platform or cutting block 416 configured to be coupledto the anterior flange 420 of the femoral trial 410. It should beappreciated that the system 10 may include a number of components 410,412 and platforms 416 corresponding to patients having femoral bones ofvarying sizes. In that way, a surgeon will be able to select thecomponents and other instruments that most-closely match the patient'sbony anatomy. As described in greater detail below, the surgeon may usethe components 410, 412 and the platform 416 to prepare the distal endof a patient's femur to receive the femoral prosthetic componentsdescribed above in regard to FIG. 1.

The femoral trial component 410 is a monolithic body formed from ametallic material such as, for example, titanium alloy or cobalt chromealloy, or other suitable biocompatible materials. The component 410includes an anterior flange 420 and a pair of curved arms 422, 424extending distally away from the anterior flange 420. Each of the arms422, 424 extends to a posterior tip 426, and the posterior tips 426 areconnected by a posterior plate 428. It should be appreciated that inother embodiments the posterior plate may be omitted. In theillustrative embodiment, the anterior flange 420, arms 422, 424, andposterior plate 428 cooperate to define a central passageway 430extending through the trial component 410.

As shown in FIGS. 2-5, the trial component 410 includes a plurality ofmounting holes and slots 440 that permit the attachment of othersurgical instruments, including the femoral trial insert (box trial)component 412 and the platform 416. The mounting holes 440 include apair of oblong openings 442 defined in the anterior flange 420, and alocking slot 444 positioned between the openings 442. In theillustrative embodiment, the oblong openings 442 are sized to receive apair of corresponding flanges 446 of the cutting platform 416, while thelocking slot 444 is sized to receive a movable locking arm 448 of thecutting platform 416, as described in greater detail below.

The mounting holes 440 also include a pair of apertures 450, 452 definedin the arms 422, 424, respectively, which open into the centralpassageway 430. As shown in FIGS. 2-3, the base surface 454 of each ofthe apertures 450, 452 has a through hole 456 defined therein. In theillustrative embodiment, a plurality of threads 458 line the holes 456,and the threads 458 are sized to receive a corresponding pair offasteners such as, for example, a pair of retained screws 460, of thebox trial component 412, as described in greater detail below.

As shown in FIGS. 2-3, the apertures 450, 452 are defined in a distalsurface 470 of each of the arms 422, 424. Each of the arms 422, 424 havea curved anterior surface 472 that extends from the distal surface 470to the anterior flange 420 and a curved posterior surface 474 thatextends posteriorly away from the distal surface 470 to the posteriortip 426. The surfaces 470, 472, 474 and the anterior surface 476 of theanterior flange 420 are configured to contact an insert trial component730 to permit a surgeon to evaluate the range of motion prior toselecting a final set of prosthetic components. In the illustrativeembodiment, the contact surfaces of the femoral trial component 410 areshaped to match to the shape of corresponding surfaces of a femoralprosthetic component corresponding to the size of the trial component410.

The femoral trial component 410 also includes a plurality of cuttingslots sized and shaped to guide a surgical saw during the surgicalprocedure to ensure a predetermined amount of bone is removed with eachcut. As shown in FIG. 2, each of the arms 422, 424 includes a pluralityof distal cutting slots 480, which are defined in the curved anteriorsurfaces 472 of the arms 422, 424. Each of the slots 480 corresponds toa different level of distal resection of the femoral bone, with thedistal-most slot being used to remove the least amount of bone duringthe cutting operation and the proximal- or anterior-most slot being usedto remove the greatest amount of bone. As shown in FIG. 3, each of thearms 422, 424 also includes a plurality of posterior cutting guide slots482, which are defined in the curved posterior surfaces 474 of the arms422, 424. Each of the slots 482 corresponds to a different level ofposterior resection of the femoral bone.

The trial component 410 also includes a plurality of guide holes 484sized to permit the passage of fixation pins 486 (see FIG. 6). Suchfixation pins may be used to temporarily secure the trial component 410to the patient's femur during a procedure.

Referring now to FIG. 5, the trial component 410 also includes abone-facing side 490, which includes surfaces configured to engage thedistal end of a patient's femur. The surfaces include an anteriorfixation surface 492 positioned opposite the anterior surface 476 of theflange 420. A pair of anterior chamfer surfaces 494 (one for each of thearms 422, 424) extend between the anterior fixation surface 492 and thedistal fixation surfaces 496 of the arms 422, 424. Each of the arms 422,424 also includes a posterior chamfer fixation surface 498 extendingbetween the distal fixation surface 496 and a posterior fixation surface500. As shown in FIG. 5, the cutting guide slots 480, 482 extend throughthe fixation surfaces 492, 494, 496, 498, 500 to permit a cutting saw toengage the patient's bone.

In the illustrative embodiment, the surfaces 496, 500 also includemounting slot 502, 504, respectively, which are sized to receivemounting pins or posts 908 of femoral augment trials 506 (see FIGS. 14and 21-23). It should be appreciated that the system 10 may include avariety of differently-sized femoral augment trials corresponding todifferent sizes of femoral augment prosthetic components.

Returning now to FIG. 2, the instruments 14 also include a number offemoral insert trial components, including the box trial component 412shown in FIG. 2 and the post trial component 712 (see FIGS. 15-16),which are configured to be separately attached to the femoral trialcomponent 410. In the illustrative embodiment, the box trial component412 includes a central body 510 sized to be positioned in the centralpassageway 430 of the trial component 410. The body 510 includes ananterior flange 512 having a surface shaped to match the patella surfaceof a corresponding femoral prosthetic component. The body 510 alsoincludes a pair of arms 514 extending from the flange 512. Each arm 514also includes a curved surface 516 shaped to match a correspondingsurfaces of the femoral prosthetic component. In that way, when the boxtrial component 412 is secured to the femoral trial component 410, thecomponents 410, 412 may cooperate to permit a surgeon to evaluate therange of motion and select a set of prosthetic components.

The box trial component 412 has a pair of mounting flanges 520, 522 thatextend outwardly from the arms 514. The mounting flanges 520 are sizedand shaped to be received in the apertures 450, 452 of the femoral trialcomponent 410, as described in greater detail below. A proximal wall 524extends between the pair of arms 514 and cooperates with the arms 514and the anterior flange 512 to define a notch 526 in the box trialcomponent 412. The notch 526 is sized to receive a spine 738 (see FIG.19) of an insert trial component 730. As shown in FIG. 1, the box trialcomponent 412 also includes a posterior cam 528 that is configured toarticulate with the spine 738 over a range of flexion.

The box trial component 412 also includes a pair of fasteners 460, whichare attached to the flanges 520 and are configured to be received in thethreaded holes 456 of the trial component 410 to secure the box trialcomponent 412 thereto. As shown in FIG. 2A, each fastener 460 includes ahead 550 and an elongated body 552 extends from the head 550. Theelongated body 552 includes a plurality of threads 554 configured toengage the threaded surface 458 of the hole 456 defined in the femoraltrial component 410. Each fastener 460 also includes an annular plate558 that extends outwardly from the head 550 to attached the fastener460 to the flange 520 of the femoral trial insert component 412.

Each flange 520 of the femoral trial insert component 412 includes adistal surface 560 that is shaped to match the posterior surfaces 474 ofthe femoral trial component 410. Each flange 520 also has an opening 562defined in the distal surface 560, and an inner wall 564 that extendsinwardly from the opening 562 to define a passageway 566 extendingthrough the flange 520. As shown in FIG. 2A, the fastener 460 isretained in the passageway 566. In the illustrative embodiment, theinner wall 564 includes a distal section 568 and a central section 570that is larger than the distal section 568. The distal section 568 isalso smaller in diameter than the diameter of the annular plate 558 ofthe fastener 460 to retain the fastener 460 into the passageway 566. Theplate 558 also includes a chamfered proximal edge 572 such that, duringassembly, an assembler may press the chamfered proximal edge 572 intothe opening 562 to advance the fastener 460 into the passageway 566. Theplanar distal edge 574 of the plate 558 prevents removal of thefasteners 460.

In the illustrative embodiment, the femoral trial component 410 and thebox trial component 412 include additional features to prevent thecomponent 410, 412 from being improperly assembled. As shown in FIG. 3,a pair of notches 530, 532 are defined in the outer perimeter of theaperture 450 of the femoral trial component 410. A corresponding pair oftabs 534, 536, respectively, extend outwardly from the flange 522 of thebox trial component 412 and are sized to be received in the notches 530,532. As shown in FIG. 3, the other aperture 452 of the femoral trialcomponent 410 lacks any such notches so that a surgeon would be unableto assemble the components 410, 412 with the flange 522 in the aperture452. It should be appreciated that the notches of the femoral trialcomponent and the flanges of the box trial component may be moved todifferent positions depending on the component sizes. In that way, thesefeatures may be used to ensure that only the box trial component thathas the same size as the femoral trial component may be secured to thatfemoral trial component. It should also be appreciated that otherfeatures may be used to prevent improper assembly of the components.

Returning again to FIG. 2, the instruments 14 also include a cuttingguide platform 416 having a cutting guide surface 576. The platform 416includes a body 540 including a posterior surface 542 shaped to engagethe anterior surface 476 of the flange 420 such that the cutting guidesurface 417 is positioned coplanar with a distal surface 684 of theanterior flange 420 and is aligned with the posterior plate 428 toprevent further posterior movement of a cutting saw blade, when thecutting saw blade is advanced posteriorly along the cutting guidesurface 576. In the illustrative embodiment, the posterior plate 428includes a groove 690 that is coplanar with the distal surface 684 ofthe anterior flange 420. In some embodiments, the posterior plate 428includes a visual indicator that is coplanar with the distal surface 419of the anterior flange 420. As described above, the platform 416 alsoincludes a pair of flanges 446, which extend outwardly from theposterior surface 542. The platform 416 also includes a lockingmechanism 544 configured to secure the cutting platform 416 to the trialcomponent 410. In the illustrative embodiment, the locking mechanism 544includes the locking arm 448 (and its engagement tab) and auser-operated button 546 attached to the body 540. A spring or otherbiasing element 548 biases the button 546 in the position shown in FIG.2.

When the posterior surface 542 of the platform 416 is engaged with theanterior surface 476 of component 410, the flanges 446 are received inthe slots 442 defined in the component 410, and the engagement tab ofthe locking arm 448 engages the anterior fixation surface 492 of theflange 420, thereby securing the platform 416 to the component 410. Todetach the platform 416 from the component 410, the surgeon may depressthe button 546, thereby compressing the spring 548 and rotating thelocking arm 448 out of engagement with the fixation surface 492. Thesurgeon may then withdraw the locking arm 448 and flanges 446 from thecomponent 410 before releasing the button 546.

As described above, the instruments 14 may be used to surgically preparea patient's femur to receive a prosthetic femoral component 20 and oneof the stem components 44. In the illustrative embodiment, theinstruments 14 may be used in a revision procedure in which a primaryimplant has been removed from a distal end of the patient's femur. Asshown in FIG. 6, the distal end 600 of a patient's femur 602 in arevision procedure includes a plurality of surfaces 604 that had beenpreviously-shaped to receive the primary implant. During a revisionprocedure, the surfaces 604 are resected to prepare the distal end 600to receive the prosthetic femoral component 20. FIGS. 6-19 and 23illustrate a number of exemplary steps of a procedure forsurgically-preparing the distal end 600 during a revision procedure. Itshould be appreciated that any surgical procedure may include additionalor fewer steps depending on the state of the patient's bony anatomy andthe preferences of the surgeon.

Referring now to FIG. 6, a surgeon may select an appropriately-sizedfemoral trial component 410 to be positioned on the distal end 600 ofthe patient's femur 602. When the surgeon has selected a trial component410, the surgeon may advance the trial component 410 over the distal end600 to engage the fixation surfaces 492, 494, 496, 498, 500 of the trialcomponent 410 with the distal end 600. The surgeon may then secure thetrial component 410 to the patient's femur 602 via one or more fixationpins 486. To do so, surgeon may align a fixation pin 486 with one of theguide holes 484 and then advance the pin 486 through the guide hole 484into the patient's femur 602. With the femoral trial component 410attached to the bone, the surgeon may use it to perform a reamingoperation on the patient's femur 602. The surgeon may also perform oneor more resections using the cutting guide slots 480, 482 of the trialcomponent 410.

As shown in FIG. 7, a reaming guide 610 may be attached to the trialcomponent 410 via the apertures 450, 452 in a manner similar to thatdescribed above in regard to the box trial component 412. The reamingguide 610 includes a barrel-shaped body 612 and a pair of mountingflanges 520 that extend outwardly from one end of the body 612. Themounting flanges 520 are sized and shaped to be positioned within theapertures 450, 452 and include retained fasteners 460 configured to bereceived in the threaded holes 456 of the trial component 410. A centralcylindrical passageway 614 extends through the body 612 to permit thepassage of a surgical reamer. In the illustrative embodiment, thereaming guide 610 also includes an adapter 620 sized to be positioned inthe central passageway 614. As shown in FIG. 7, the adapter 620 has acentral cylindrical passageway 622 of smaller diameter than thepassageway 614. In that way, the reaming guide 610 may be used withreamers of varying size.

Referring now to FIG. 8, one surgical reamer 630 for use with thereaming guide 610 is shown. The reamer includes an elongated shaft 632having a plurality of cutting flutes 634 formed at a distal end 636. Atool shank (not shown) is formed at the opposite end and is sized to besecured to a surgical drill or other rotary surgical instrument. Theelongated shaft 632 includes a cylindrical outer surface 640 thatextends from the cutting flutes 634 to the tool shank. A plurality ofspaced-apart annular slots 642 are defined in the outer surface 640. Inthe illustrative embodiment, the position of each annular slot 642 alongthe outer surface 640 corresponds to a desired reaming depth of thereamer 630, which, in turn, corresponds to a desired depth for a stemcomponent 44.

The outer surface 640 of the shaft 632 defines a diameter 644 of thereamer 630. In the illustrative embodiment, the instrument 14 includes aplurality of different reamers having a similar configuration to reamer630 but with larger diameters.

The system 10 also includes a moveable depth stop 650, which may beattached to the reamer 630 at the annular slot 642 corresponding to adesired depth. In the illustrative embodiment, the depth stop 650 has acentral opening 652 and a plurality of alignment tabs 654 extendinginwardly into the opening 652. The central opening 652 has a diametercorresponding to the diameter of the central passageway 614 of thereaming guide 610, which corresponds to the largest diameter reamer inthe system 10. Each reamer, including the reamer 630, includes aplurality of longitudinal slots 660 corresponding in number to thenumber of alignment tabs 654 of the depth stop 650. Each of thelongitudinal slots 660 includes apertures or notches 664 formed therein.The notches 664 are offset from the annular slots 642 and correspond toan annular slot 624 (i.e., desired reaming depth).

As shown in FIG. 8A, the bottom surfaces 666 of the slots 660 of eachreamer (illustratively reamer 630 and another reamer 668 having a largerdiameter shown in broken line) are positioned and sized to be receivedin an alignment opening 662 defined by the tips of the tabs 654 so thata single depth stop 650 may be used with any size reamer. In theillustrative embodiment, opposing bottom surfaces 666 define a distance669 that is the same for every reamer so that a single depth stop 650may be used with all of the reamers.

In the illustrative embodiment, the depth stop 650 includes a movableplate 670 is connected to a pin 674 that may be advanced into and out ofengagement with one of the notches 664 to secure the depth stop at adesired position indicated by the annular slot 642. The pin 674 extendsfrom a flange 676 that is aligned with one of the tabs 654 of the depthstop 650.

As shown in FIG. 8A, the depth stop 650 includes a body 850 defining acavity 852. The alignment opening 662 extends through the body 850 andthrough the cavity 852. The moveable plate 670 is positioned within thecavity 852. The moveable plate 670 includes a button 854 extending froman actuating side 856 of the depth stop 650. Springs 856 extend betweenthe moveable plate 670 and a sidewall 858 formed on a retaining side 860of the depth stop 650 to bias the moveable plate 670 toward anengagement position. A pin in the body 850, which is received in anopening defined in the moveable plate 670, couples the moveable plate670 to the body 850.

The body 850 of the depth stop 650 includes a pair of planar walls 862that are configured to engage the guide adapter 620. A plurality ofalignment tabs 654 extend from each wall 862. In the illustrativeembodiment, the depth stop 650 includes 8 alignment tabs arrangeorthogonally to each other. Four opposing alignment tabs 654 (positionedon each side of the plate 670) extend parallel to the pin 674 while theother tabs 654 (also positioned on each side of the plate 670) extendorthogonal to the pin 674.

To secure the depth stop 650 to the reamer 630, the depth stop 650 isadvanced along a length of the reamer 630 such that the tabs 654 advancealong the longitudinal slots 660. While moving the depth stop 650 alongthe length of the reamer 630, the button 854 of the depth stop 650 isdepressed to move the moveable plate 670 such that the pin 674 isdisengaged from the reamer 630. The depth stop 650 is aligned with anannular slot 642 that corresponds to a desired depth. After aligning thedepth stop 650, the button 854 of the depth stop 650 is released suchthat the springs 856 bias the moveable plate 670 to position the pin 674within the corresponding notch 664 in the longitudinal slot 660 of thereamer 630.

As shown in FIG. 9, when the depth stop 650 is properly positioned atthe desired annular slot 642 of the reamer 630, the reamer may beadvanced into the central cylindrical passageway 614 of the reamingguide adapter 620 and into contact with the distal end 600 of thepatient's femur 602. The surgeon may continue to advance the reamer 630deeper into the patient's femur until the depth stop 650 contacts theguide adapter 620, thereby forming a surgically-prepared passageway 672in the distal end 600 of the femur 602, as shown in FIG. 10.

Referring now to FIG. 10, when the surgeon has a passageway 672 of thedepth and diameter desired, the reaming guide 610 may be detached fromtrial component 410. The surgeon may then use a surgical saw 682 performa “box cut” of the distal end 600 of the patient's femur 602. Asdescribed above, the trial component 410 includes a central passageway430 defined by inner surfaces of the anterior flange 420, the arms 422,424, and the posterior plate 428 of the component 410. In theillustrative embodiment, the surfaces 684 defining the centralpassageway 430 are substantially planar surfaces and act as cuttingguide surfaces for the surgical saw 682.

To provide additional support for the distal resection of the box cut,the surgeon may attach the cutting guide platform 416, as shown in FIG.11. The planar surface 686 of the platform 416 lines with the surface684 of the anterior flange 420 to provide an extended cutting guidesurface for the resection. As shown in FIG. 12, the posterior plate 428of the trial component 410 includes a groove 690 extending between thearms 422, 424. The groove 690 is sized to receive the cutting edge 692of the surgical saw 682, thereby acting as a capture for the saw 682.Additionally, the groove 690 provides the surgeon with a visualindication that the desired resection depth has been achieved. When theresection is completed, the surgeon may remove the femoral trialcomponent 410 from the patient's bone.

Referring now to FIGS. 13A and 13B, the surgeon may attach the box trialcomponent 412 to the femoral trial component 410. To do so, the surgeonmay align the box trial component 412 with the central passageway 430 ofthe trial component 410, as shown in FIG. 13A. The surgeon may thenadvance the body 510 of the box trial component 412 into the centralpassageway 430 and the mounting flanges 520 into their correspondingapertures 450, 452. As described above, improper alignment of thecomponents 410, 412 is prevented by the combination of notches 530, 532and tabs 534, 536 formed on the components 410, 412, respectively. Withthe flanges 520 positioned in the apertures 450, 452, surgeon mayadvance the fasteners 460 into the threaded holes 456, thereby securingthe box trial component 412 to the femoral trial component 410. Itshould be appreciated that the box trial component 412 may be attachedbefore the femoral trial component 410 is positioned on the bone orafter the component 410 is in position.

As shown in FIG. 14, the box trial component 412 includes a stem post700 configured to be secured to a stem trial 702. It should beappreciated that the system 10 may include a number of different stemtrials 702 having different lengths and different diameters, sized tofit bones of varying sizes. To secure the stem trial 702 to the post700, one end of the stem trial 702 is aligned with an opening 704defined in the stem post 700 and then advanced into the opening 704. Asshown in FIGS. 13A and 13B, a threaded fastener 706 is advanced betweenthe arms 514, 516 of the box trial component 412 and into the passagewayof the stem post 700. The fastener 706 is threaded into an opening (notshown) defined in the end of the stem trial 702 to secure the stem trial702 to the trial component 412.

Turning again to FIG. 14, the surgeon may optionally attach one or morefemoral augment trials 506 to the femoral trial component 410. To do so,surgeon may align a tab (not shown) of the trial 506 with one of themounting slots 502 defined in the trial component 410. The surgeon maythen advance the trial 506 into the mounting slot 502, thereby securingthe trial components together. The surgeon may introduce the assemblyinto the surgically prepared distal end 600 of the patient's femur 602and perform a trial reduction to evaluate the range of motion with thefemoral trial component 410 attached to the bone. Alternatively, thetrials 506 may be inserted into the slots 502 with the femoral trialcomponent 410 already positioned on the bone.

Referring to FIG. 20, each curved arm 422, 424 includes the mountingslot 502 defined in its distal bone-facing surface 496. The mountingslot 502 extends inwardly from an outer edge 900 of the arm 422, 424. Itshould be appreciated that the outer edge may be the medial or lateraledge of the femoral trial component. A channel 902 is defined in thedistal bone-facing surface 496 of each arm 422, 424 and extends inwardlyfrom the outer edge 900 parallel to the slot 502. The channel 902 ispartially defined by a tapered surface 904. An aperture 906 is definedin the distal bone-facing surface 496 of each arm 422, 424 and is spacedapart from the channel 902.

Additionally, each curved arm 422, 424 includes the mounting slot 502defined in its posterior bone-facing surface 500. The mounting slot 502extends inwardly from an outer edge 900 of the arm 422, 424. A channel902 is defined in the posterior bone-facing surface 500 of each arm 422,424 and extends inwardly from the outer edge 900 parallel to the slot502. The channel 902 is partially defined by a tapered surface 904. Anaperture 906 is defined in the posterior bone-facing surface 500 of eacharm 422, 424 and is spaced apart from the channel 902.

Referring to FIGS. 21 and 22, a plurality of augment trial components506 are sized to be positioned on one of the distal bone-facing surface496 or the posterior bone-facing surface 500 of the arms 422, 424.Particularly, the augment trial components 506 include distal augmenttrial components and posterior augment trial components. The augmenttrial components 506 include at least one magnet and may be made from amagnetic material.

Each augment trial component 506 has a different thickness 507 definedbetween a planar base surface 903 and a planar bottom surface 907. In adistal augment trial component 506, the thickness 507 is equal to aspacing 509 (shown in FIG. 14) defined between the bone-facing surfaces496 and the distal cutting slots 480 of each arm 422, 424. In aposterior augment trial component 506, the thickness 507 is equal to aspacing 511 (shown in FIG. 14) defined between the bone-facing surfaces500 and the posterior cutting slots 482 of each arm 422, 424. The planarbase surface 903 is configured to engage one of the bone-facing surfaces496, 500 of the curved arms 422, 424. In a distal augment trialcomponent 506, a flange 913 extends from a front 915 of the component506. It should be noted that a posterior augment trial component 506does not include the flange 913. The trials 506 include mounting posts908 and a peg 910 extending outwardly from the planar base surface 903.The mounting posts 908 have substantially cylindrical ends 915.

The slots 502 formed in the arm 422, 424 are sized to receive themounting posts 908 of one of the plurality of trials 506. Particularly,the slots are sized and shaped to receive the cylindrical ends 915 ofthe mounting posts 908. The mounting posts 908 include a pin 914 that isoperable to retain the cylindrical ends 915 of the mounting posts 908 inthe slot 502 of the curved arm 422, 424. The peg 910 is sized to bereceived in the channel 902. Particularly, the tapered surface 904 ofthe channel 902 is configured to engage the peg 910 of each trial 506 asthe trial 506 is advanced into the arm 422, 424. The aperture 906 issized to receive the peg 910 of each trial 506 when the trial 506 isfully advanced into the slot 502.

As illustrated in FIG. 23, after positioning the femoral trial component410 on the patient's femur, the surgeon may advance the trial 506 intoone of the mounting slot 502 of the component 410. As the trial 506 isadvanced medially or laterally from the outer edge into the mountingslot 502, the peg 910 engages the tapered surface 904, thereby causingthe trial 506 to tilt relative to the bone-facing surface of the femoraltrial component. The peg 910 may exit the channel 902, slide along thebone-facing surface, and then drop into the aperture 906. In thisposition, the peg 910 of the trial 506 is retained in the aperture 906component 410 to retain the trial 506 and prevent the trial 506 fromretracting through the mounting slot 502. Additionally, the trial 506magnetically couples to the component 410 to further retain the trial506.

Returning to FIGS. 15A-B, the femoral trial component 410 may beutilized with other trial components including, for example, a posttrial component 712. Similar to the box trial component 412, the posttrial component 712 includes an anterior flange 512 and a pair of arms514 extending from the flange 512. A pair of mounting flanges 520 extendoutwardly from the arms 514 and are configured to be received in theapertures 450, 452 of the femoral trial component 410. A stem post 700extends away from the arms 514 of the post trial component 712.

The system 10 also includes a boss trial 714 configured to be secured tothe stem post 700 via the threaded fastener 706. As shown in FIG. 16,the boss trial 714 has a threaded bore 716 sized to receive acorresponding threaded shaft 718 of a stem trial component 720. A drivertool 722 may be used to thread the stem trial component 720 onto theboss trial 714.

Referring now to FIG. 17 the assembled trial component 410, post trialcomponent 712, and stem trial component 720 may be advanced onto thedistal end 600 of the patient's femur 602. It should be appreciated thatthe post trial component 712, like the other femoral trial insertcomponents, may be attached before the femoral trial component 410 ispositioned on the bone or after the component 410 is in position. Asshown in FIG. 18, with the assembly positioned on the distal end 600, asurgeon may use a surgical saw 682 to resect the patient's bone. To doso, the surgeon may position the saw 682 in the one of the cutting guideslots 480 to remove a desired amount of bone from the distal end 600. Asshown in FIG. 17, the surgeon may utilize the cutting guide slot 480 toremove sufficient bone material to permit the insertion of an augmenttrial 506, as described above. The surgeon may continue the resection toshape the bone as desired to receive a femoral prosthetic component 20.

As described above, the femoral trial component 410 and the box trialcomponent 412 and/or the post trial component 712 may be used during atrial reduction to evaluate the range of motion. As shown in FIG. 19,the femoral trial component 410 is configured to engage a tibial inserttrial component 730 positioned on a tibial base trial component 732,which is attached to the proximal end 734 of a patient's tibia 736. Anexemplary description of trial reduction and preparation of patient'stibia is disclosed in U.S. Pat. No. 9,028,501, issued on May 12, 2015and entitled “TIBIAL ORTHOPAEDIC SURGICAL INSTRUMENTS AND METHOD OFUSING SAME” by Kyle B. Thomas et al., which is incorporated herein byreference. The tibial insert trial component includes a pair of concavecurved surfaces that engage and articulate with the surfaces of thefemoral trial component 410 and the box trial component 412 and/or thepost trial component 712 over a range of flexion from extension toflexion to evaluate the range of motion and determine theappropriately-sized prosthesis.

It should be appreciated that the surgeon may perform an initial trialreduction with the post trial component 712 and stem trial component720. The surgeon may then remove the post trial component 712 and stemtrial component 720 while leaving the femoral trial component 410 inposition on the patient's femur. The surgeon may then perform thereaming operation described above in regard to FIGS. 7 and 9, performthe box cut operation described above in regard to FIGS. 10-12, and thenattach the box trial component 412 before performing an additional trialreduction and/or augment resection as described.

While the foregoing exemplary embodiments have been described to have aseparable tibial tray and a tibial tray insert, it is to be understoodthat the tibial tray may include condyle receiver bearing surfaces thatobviate the need for a separate tibial tray insert.

Following from the above description and invention summaries, it shouldbe apparent to those of ordinary skill in the art that, while themethods and apparatuses herein described constitute exemplaryembodiments of the present invention, the invention contained herein isnot limited to this precise embodiment and that changes may be made tosuch embodiments without departing from the scope of the invention asdefined by the claims. Additionally, it is to be understood that theinvention is defined by the claims and it is not intended that anylimitations or elements describing the exemplary embodiments set forthherein are to be incorporated into the interpretation of any claimelement unless such limitation or element is explicitly stated.Likewise, it is to be understood that it is not necessary to meet any orall of the identified advantages or objects of the invention disclosedherein in order to fall within the scope of any claims, since theinvention is defined by the claims and since inherent and/or unforeseenadvantages of the present invention may exist even though they may nothave been explicitly discussed herein.

The invention claimed is:
 1. An orthopaedic surgical system comprising:a femoral trial component configured to be coupled to asurgically-prepared distal end of a patient's femur, the femoral trialcomponent comprising an anterior flange, and a pair of curved armsextending away from the anterior flange, each arm including a distalbone-facing surface, a plurality of augment trial components, eachaugment trial component being sized to be positioned on the distalbone-facing surface and including a mounting post and a magnet, whereineach curved arm includes a slot defined in its distal bone-facingsurface that extends inwardly from an outer edge, the slot being sizedto receive the mounting post of one of the plurality of augment trialcomponents, and wherein each augment trial component has a differentthickness, and the curved arms of the femoral trial component include aplurality of distal cutting slots, each distal cutting slot being spacedapart from the distal bone-facing surface by a distance equal to thethickness of one of the augment trial components.
 2. The orthopaedicsurgical system of claim 1, wherein: each curved arm includes a channelthat is defined in its distal bone-facing surface and extends inwardlyfrom the outer edge parallel to the slot, and each augment trialcomponent includes a peg sized to be received in the channel.
 3. Theorthopaedic surgical system of claim 2, wherein the channel is partiallydefined by a tapered surface configured to engage the peg of eachaugment trial component.
 4. The orthopaedic surgical system of claim 3,wherein each curved arm includes an aperture that is defined in itsdistal bone-facing surface and is spaced apart from the channel, eachaperture being sized to receive the peg of each augment trial component.5. The orthopaedic surgical system of claim 4, wherein each augmenttrial component includes a planar base surface configured to engage thedistal bone-facing surface of each curved arm, and the mounting post andthe peg extend outwardly from the base surface.
 6. The orthopaedicsurgical system of claim 1, wherein the mounting post includes a pinoperable to retain the mounting post in the slot of the curved arm. 7.The orthopaedic surgical system of claim 1, further comprising a femoraltrial insert component configured to be secured to the femoral trialcomponent, the femoral trial insert component including a main bodysized to be positioned between the pair of curved arms.
 8. Theorthopaedic surgical system of claim 7, further comprising: a tibialbase plate sized to be positioned on a proximal surface of a patient'stibia, and an insert trial configured to be attached to the tibial baseplate, the insert trial including a pair of proximal curved surfacesconfigured to articulate with the curved arms of the femoral trialcomponent and the femoral trial insert component.
 9. An orthopaedicsurgical system comprising: a femoral trial component configured to becoupled to a surgically-prepared distal end of a patient's femur, thefemoral trial component comprising an anterior flange, and a pair ofcurved arms extending away from the anterior flange, each arm includinga distal bone-facing surface, a plurality of augment trial components,each augment trial component being sized to be positioned on the distalbone-facing surface and including a mounting post and a magnet, aplurality of posterior augment trial components, each posterior augmenttrial component including a mounting post and a magnet, wherein eachcurved arm includes a slot defined in its distal bone-facing surfacethat extends inwardly from an outer edge, the slot being sized toreceive the mounting post of one of the plurality of augment trialcomponents, wherein each arm includes a posterior bone-facing surfaceand a posterior slot defined in its posterior bone-facing surface thatextends inwardly from the outer edge, the posterior slot being sized toreceive the mounting post of one of the plurality of posterior augmenttrial components, and wherein each posterior augment trial component hasa different thickness, and the curved arms of the femoral trialcomponent include a plurality of posterior cutting slots, each posteriorcutting slot being spaced apart from the posterior bone-facing surfaceby a distance equal to the thickness of one of the posterior augmenttrial components.
 10. The orthopaedic surgical system of claim 9,further comprising a femoral trial insert component configured to besecured to the femoral trial component, the femoral trial insertcomponent including a main body sized to be positioned between the pairof curved arms.
 11. The orthopaedic surgical system of claim 10, furthercomprising: a tibial base plate sized to be positioned on a proximalsurface of a patient's tibia, and an insert trial configured to beattached to the tibial base plate, the insert trial including a pair ofproximal curved surfaces configured to articulate with the curved armsof the femoral trial component and the femoral trial insert component.12. An orthopaedic surgical system comprising: a femoral trial componentconfigured to be coupled to a surgically-prepared distal end of apatient's femur, the femoral trial component comprising an anteriorflange, and a pair of curved arms extending away from the anteriorflange, each arm including a distal bone-facing surface, a plurality ofaugment trial components, each augment trial component being sized to bepositioned on the distal bone-facing surface and including a mountingpost and a magnet, a femoral trial insert component configured to besecured to the femoral trial component, the femoral trial insertcomponent including a main body sized to be positioned between the pairof curved arms, wherein each curved arm includes a slot defined in itsdistal bone-facing surface that extends inwardly from an outer edge, theslot being sized to receive the mounting post of one of the plurality ofaugment trial components.
 13. The orthopaedic surgical system of claim12, further comprising: a tibial base plate sized to be positioned on aproximal surface of a patient's tibia, and an insert trial configured tobe attached to the tibial base plate, the insert trial including a pairof proximal curved surfaces configured to articulate with the curvedarms of the femoral trial component and the femoral trial insertcomponent.
 14. An orthopaedic surgical system comprising: a femoraltrial component configured to be coupled to a surgically-prepared distalend of a patient's femur, the femoral trial component comprising ananterior flange, and a pair of curved arms extending away from theanterior flange, a plurality of augment trial components, each augmenttrial component including a peg and a magnet, and wherein each curvedarm includes an aperture defined in a bone-facing surface that is sizedto receive the peg of one of the plurality of augment trial components,wherein each augment trial component has a different thickness, and thecurved arms of the femoral trial component include a plurality ofcutting slots, each cutting slot being spaced apart from the bone-facingsurface by a distance equal to the thickness of one of the augment trialcomponents.
 15. The orthopaedic surgical system of claim 14, wherein thebone-facing surface is a distal bone-facing surface.
 16. The orthopaedicsurgical system of claim 14, wherein the bone-facing surface is aposterior bone-facing surface.
 17. The orthopaedic surgical system ofclaim 14, wherein: each curved arm includes a channel that is defined inits bone-facing surface, the channel extending inwardly from an outeredge of the curved arm and spaced apart from the aperture, and thechannel is sized to receive the peg of each augment trial component. 18.The orthopaedic surgical system of claim 17, wherein: each augment trialcomponent includes a mounting post, and each curved arm includes a slotdefined in the bone-facing surface that extends inwardly from the outeredge, the slot being sized to receive the mounting post of one of theplurality of augment trial components.
 19. The orthopaedic surgicalsystem of claim 14, further comprising a femoral trial insert componentconfigured to be secured to the femoral trial component, the femoraltrial insert component including a main body sized to be positionedbetween the pair of curved arms.
 20. The orthopaedic surgical system ofclaim 19, further comprising: a tibial base plate sized to be positionedon a proximal surface of a patient's tibia, and an insert trialconfigured to be attached to the tibial base plate, the insert trialincluding a pair of proximal curved surfaces configured to articulatewith the curved arms of the femoral trial component and the femoraltrial insert component.